Cytochrome C1

Cytochrome C1 is formed in the cytosol and targeted to the mitochondrial intermembrane space. It is one of the constituents of complex III, which forms the third proton pump in the mitochondrial electron transport chain.

Cytochrome c₁ is a subunit of the electron transport chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex), which consists of the products of one mitochondrially encoded gene, MTCYTB (mitochondrial cytochrome b) and ten nuclear genes: UQCRC1, UQCRC2, Cytochrome c1, UQCRFS1 (Rieske protein), UQCRB, UQCRQ ("11kDa protein"), UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and UQCR ("Rieske-associated protein").